White Vinegar takes at minimum 1 hour to kill the mold once you apply the Vinegar to the mold.
So after you spray the vinegar onto the mold allow the vinegar to sit on the mold for at least 1 hour so it has enough time to work on the mold.
Then the mold should be able to come off easily when you use a rag or scrub brush and sometimes you might need to spray the mold again with vinegar and let it sit another hour depending on how much mold you have.
After an hour or two the mold should come right off with water and a scrub brush.